So-called data centers are unique buildings designed specifically to house large numbers of computers. These special buildings are designed to provide environmental conditions conducive to computer interconnectivity, longevity, cooling, and power consumption. The computers that are stored in a data center are generally enclosed in standardized enclosures that mount in racks described by EIA-310-D, CEA-310-E, and sub-specifications of IEC 60297. Such computers within the 19-inch form factor are generally referred to as “servers” according to data center vernacular.
Since data centers may contain many servers, it is not possible to individually control or inspect each one of them. To allow the remote monitoring and control of each server, a so-called conventional Out-Of-Band (OOB) management component is provided. The OOB management component is powered independently of the server motherboard and thus remains active and available so long as external power is applied to the server. There is an evolving standard to interface to the OOB management system of servers called Red Fish™.
To provide higher reliability, computers in data centers typically contain multiple power supplies. The power supplies utilized within the computers are generally of a Switch Mode Power Supply (SMPS) type. The SMPS internal architecture utilizes an electronic switch, usually a semiconductor such as a transistor or diode, to rapidly turn on and off the input source of power. The switch is generally called a “chopper” in the power supply industry vernacular. In a “Buck Mode” SMPS, the input voltage is higher than the output voltage. Because the input voltage is generally greater than 100 volts and the computer semiconductors run at voltages between 1 and 12 volts, this is the most common type of SMPS used in servers. Buck mode SMPS are easily disabled by removing the signal that drives the switching device.
Switch mode power supplies utilize output capacitors to smooth out the converted voltage. The difference in the output signal between a pure Direct Current (DC) power source, such as a battery, and a rectified AC (Alternating Current) source is called the ripple voltage. The capacitance of the output capacitor, measured in Farads, plays a large part in the reduction of the voltage ripple. When the voltage across its terminals is high, charge enters the capacitor. When the voltage goes low, charge leaves the capacitor.